Recovery system for test ballistic missiles



2 Sheets-Sheet 1 M. SIEGEL ETAL RECOVERY SYSTEM FOR TEST BALLISTICMISSILES INVENTORS /%J. 6 5654 L/dJ't/d l d e, JR. BY M L. M

firro/rnw Sept. 11, 1962 Filed July 28, 1959 P 1962 M. SIEGEL ETAL3,053,479

. RECOVERY SYSTEM FOR TEST BALLISTIC MISSILES Filed July 28, 1959 2Sheets-Sheet 2 INVENTORS flfosgj $6654 BY dosfpxy gaze, JQ.

, asahs Patented Sept. 11, 1$62 3,053,479 RECOVERY SYSTEM FOR TESTBALLHSTHC MISSHLES Moses Siege! and Joseph Auer, In, Philadelphia, Pa,as-

signors to the United States of America as represented by the Secretaryof the Navy Filed July 28, 1959, Ser. No. 830,164 3 Claims. (Cl. 244-14)(Granted under Title 35, US. Code (1952), see. 266) The inventiondescribed herein may be manufactured and used by or for the Governmentof the United States of America for governmental purposes without thepayment of any royalties thereon or therefor.

This invention pertains to test launching and recovery of aerialmissiles.

Missiles of the type to which the invention relates are thin shelledcylinders weighing approximately thirty thousand pounds and about thirtyfeet in length. They are provided with an engine or other means forpropelling them, a Warhead or satellite, and instruments of varioustypes, as for navigation, collecting geophysical and aerodynamical data,etc.

Because of the flame emitted from the missile, in many instances thesite does not permit launching the missile under its own power; it isnecessary to delay starting the engine until the missile is clear of thesite. Under such conditions, an external catapulting force must beapplied to the missile to get it a safe distance away from the launchingsite. For this purpose, a launching tube is utilized from which themissile is ejected. The expansive force of a compressed fluid, such asair or some other force, released within the tube under the missilecatapults it the required height from which its engines may be safelystarted.

The difficulty encountered in many instances has been the destruction ofthe missile shortly after launching. Frequently this has been due to theinability of the missile to endure the catapulting force. For thedetermination of the causes of failure a test vehicle properlyinstrumented is catapulted and recovered. The vehicles motors are notstarted and recovery is by some means that will avoid damage to thevehicle and instruments. Among the systems used are a parachute attachedto the missile for lowering it safely, and a net for catching themissile at the climax of its flight.

In a parachute recovery system, the size and Weight of the parachutenecessary to support a thirty thousand pound missile create a problem ofstowing it on the missile. Its location affects missile performancebyadding to drag increasing missile weight and changing the missilesstability. The sites from which launching can take place also arerestricted. The missile is catapulted only about 150 feet, which isinsufficient for deploying a parachute. Additional height must beobtained by mounting the launcher on a platform, at the brink of acliff, or in some other manner to give the chute the time required todeploy. Furthermore, intricate timing devices are required for openingthe chute and cushioning bags must be provided to absorb the impact ofthe missile with the landing surface.

The use of nets to catch a catapulted missile has the advantage of notinterfering with missile flight; however, the impact with the netdamages the missile, which can be expensive considering the missilescost, or enmeshes it making it diflicult to extract the missile from thenet. Because the missile trajectory is nearly vertical, complicated netmoving mechanisms are necessary for transporting the net away from thelauncher beforemissile ejection and over the launcher for catching themissile. A consequence is that only slow sequences of launchings arepossible with net recovery systems.

It is, therefore, an object of this invention to provide an' aerial testvehicle launching and recovery system which will minimize thedifiiculties averted to in the systems discussed by providing a devicewhich will take hold of the test vehicle at the apex of its flight,applying an increasing restraining force with the descent of the vehicleand completely arrest it in mid air.

Another object of this invention is a novel test launching and recoverysystem for an aerial vehicle which substantially avoids interferencewith the flight of the vehicle and prevents impact of the vehicle withany landing surface.

A further object of the invention is a system in which the variousoperations in the process of launching and recovering an aerial testvehicle are made to occur automatically in proper sequence in responseto a single initiatory act.

Another object of this invention is a method of recovering an ejectedmissile by attaching a flexible member to the vehicle, overhauling theslack in the member with the rise of the vehicle and applying a yieldingrestraint with the descent of the vehicle so as to arrest it in mid air.

Other objects will become apparent in the specific constructionillustrated and described, it being understood that the invention is notlimited thereby, since it is capable of other embodiments. Thephraseology is for descriptive purposes and not intended to limit theinvention beyond the terms of the appended claims in view of the priorart.

In the drawing,

FIG. 1 is an elevational view of the invention illustratings, by solidlines, the missile and recovery cable in readiness for a launching andshowing, in broken lines, some positions in fli ht and recovery of themissile.

FIG. 2 is a fragment of the apparatus of the invention taken on thelines 22 of FIG. 1.

FIG. 3 is a schematic showing of the launching and recovery mechanism.

Referring to FIGS. 1 and 2 of the drawing, the reference numeral itindicates a rocket type aerial missile which is ordinarily ejected froma barrel 12 in substantially a vertical direction under the force of acompressed fluid released within the barrel beneath the rocket. Thebarrel 12 is disposed in a pit 14 although it can be placed on or abovethe ground surface as desired. The pit 14 is located substantiallybetween two upright towers, 16 and 16, which may be of steel, wood orother suitable material and are braced (not shown) by guy lines asrequired. Obviously one tower with a boom may be made to suffice. Thetowers, 16 and 16, rise above the expected ejection height of themissile 10 and are spanned by a horizontal support member which can be awire cable 18, as shown, having an end secured to the top of each tower.

Secured to the cable 18 between the towers, 16-16, is a swivelablepulley 20 over which travels a flexible member 22 such as a wire cable,chain, rope or the like. A depending end 24 of the member 22 is fastenedto a bail 26 secured to a nose part of the missile by means of bolts orrivets 28. \A nylon strap is a preferred construction for the bail 26although a steel nose ring with swivel can be used.

The other end of the flexible member 22 is led through pulleys 27 and2.9 that are secured at the top and bottom of one of the towers 16,respectively, and around a plurality of fixed and movable sheaves, 32and 34, of an arresting engine 36). After being reeved through thesheaves 32 and 34 the cable 22 is secured to an anchor (not shown) onthe engine.

The arresting engine 3t) functions as a means for taking up slack cableand an energy absorber; it has a crosshead 36 on which the movablesheaves 34 are mounted. A piston 38 is attached to the crosshead 36 andis reciprocably movable in a hydraulic cylinder 40. The fixed sheaves 32and associated cylinder 40 are fixed relative the towers, 16 and 16, andsheaves 34.

For outward movement of piston 38 hydraulic liquid is supplied to enginecylinder 40 from an accumulator tank 42 by a conduit 44 under airpressure which is conducted to the accumulator from a source (not shown)through a pipe 46. A solenoid operated valve 48, normally held closed bya spring 49, controls liquid flow from tank 42 into cylinder 40, and aone-way valve 50 prevents the return of liquid from the cylinder to thetank. Valve 50 may be a fluid metering type for regulating fluid flowinto cylinder 40 and thereby the outward movement rate of piston 38. Inthis manner take-up of cable slack may be increased or decreased, asdesired.

To permit inward movement of piston 33 a liquid escape passage fromcylinder 40 to a gravity tank 52 is provided by a conduit 54 A flowmetering valve 56 in conduit 54 is normally held closed by a spring 58;it is adjustable by turning a nut 6% so that it can be set to open onlywhen subjected to a predetermined pressure by the liquid from cylinder40. A pump 62 returns bydraulic liquid from gravity tank 52 to theaccumulator 42 through a conduit 64. A one-way.valve 66 in conduit 64prevents flow back to the pump.

The solenoid valve 48 together with a second solenoid valve 68 iscontrolled by a double pole switch 70; they are arranged to be openedwith energization of their coils which takes place with closing of theswitch 68. Current for the operation of the solenoids is obtained fromsome convenient source to which it is connected by the lines L. As isclear from the drawing, the contacts 71 and 72 which connect the linecurrent to solenoids 48 and 68, respectively, are adjustable thuspermitting a time delay, if so desired, between their energization.

Solenoid valve 68 in conduit 73 controls the flow of compressed air froma source 74 into the launcher barrel 12 which is used to eject themissile from the barrel.

In operation, missile 10, with cable 22 attached, is loaded into barrel12 and switch 70 closed. Current from lines L energizes solenoids 48 and68 thereby opening them. Compressed air from tank '74 flows throughvalve 68 into barrel 12 and ejects the missile. Opening of valve 48permits air pressure from conduit 46 to force the hydraulic liquid fromtank 42 into cylinder 40 thereby extending piston 38. This movement ofthe piston separates the fixed and movable sheaves, thereby absorbingthe slack in cable 22 created by the rise of the missile, and continuesto do so until the missile has reached the apex of its rise.

The descent of the missile pulls cable 22 from the arresting enginethereby forcing piston 38 into cylinder 40. The force produced by theweight and velocity of the missile in descent, which is transmitted tothe fluid within cylinder 40, is sufficient to cause valve 56 to beopened thereby permitting a metered flow of fluid from cylinder 40 intothe gravity tank 52. The eflect is a gradual reduction in the descent ofthe missile. Eventu- 4 ally the force is only that of the missile Weightwhich is insuflicient to open valve 56. At this time the missile will behalted at some point in mid air which can be varied by setting theadjusting nut of valve 56. Further descent of the missile may be made bymanually manipulating valve 56.

Having described the invention what is claimed is:

1. Apparatus for launching and recovering an ejected test vehiclecomprising launching means for ejecting said vehicle to a predeterminedheight, an overhead support above said predetermined height, a cablesuspended from said support, a cable take-up and arresting means, saidcable being adapted to be secured at one end to said vehicle and at theother end to said take-up and arresting means whereby upon ejection ofsaid vehicle said take-up and arresting means overhauls cable slack withrise of said vehicle and yieldingly restrains descent of said vehicle,and means for actuating said launching and takeup and arresting meanswith one initiatory act.

2. Apparatus for recovering an ejected test vehicle comprising anoverhead support, a cable suspended therefrom having an end adapted forsecuring to said vehicle, a cylinder, a crosshead, a piston extendingtherefrom reciprocable in said cylinder, the other end of said cablebeing reeved around said cylinder and crosshead, a source of fluid underpressure, conduit means connecting said source to said cylinder, one-wayvalve means in said conduit means for admitting fluid into said cylinderduring outward movement of said piston, a fluid escape passage connectedto said cylinder for discharge of fluid therefrom during inward movementof said piston, and a constant pressure valve in said fluid escapepassage for opening with a predetermined pressure.

3. Apparatus for launching and recovering a test vehicle comprising alauncher for ejecting said vehicle, a source of fluid under pressure,means connecting said source of fluid to said launcher, actuating meansin said connecting means for controlling fluid flow from said source tosaid launcher, an overhead support, a cable suspended therefrom havingan end adapted to be secured to said vehicle, a cable take-up andarresting engine having a hydraulic fluid cylinder and a piston providedwith sheaves, the other end of said cable being reeved through saidengine so that outward movement of said piston from said cylinder takesup cable slack, a source of hydraulic fluid under pressure connected tosaid engine fluid control means permitting one-way flow from said sourceof hydraulic fluid into said engine for outward movement of said piston,fluid escape means from said engine for discharging fluid flow therefromwhen a predetermined pull is applied to said cable and said piston ismoved inwardly, and means initiating said actuating and fluid controlmeans simultaneously.

References Cited in the file of this patent UNITED STATES PATENTS

